This error may occur to the user, starting the Denodo Server without having sufficient Operating System privileges to store and load objects. To avoid such scenario, I would either provide the user with read and write privilege or launch the Denodo Platform with administrator rights using “**Run as Administrator**” option.
You can also have a look at this similar [**community question**](https://community.denodo.com/answers/question/details?questionId=90670000000Cc7rAAC&title=Error+when+trying+to+create+a+new+virtual+DB), to have more information on this issue.
Hope this helps!!